Wireless communication systems provide a user device wireless access to communication services. Wireless communication systems allow users to move about and communicate over the air with access communication networks. Wireless communication devices transfer data packets with data communication networks to provide data communication services, such as internet access, media streaming, voice calls, and text messaging. End users pay for a data usage policy which determines which network services and the amount of data the end user is authorized to use. These data usage policies for each end user are monitored so users do not use network services and data they are not authorized to use.
Long-Term Evolution (LTE) is a popular wireless data technology. Using LTE, a wireless User Equipment (UE) exchanges data with a Mobility Management Entity (MME) over an evolved-NodeB (eNodeB) base station. MME transfers a Diameter request message to a Home Subscriber System (HSS) and receives a Diameter Response indicating an Access Point Name (APN) and associated APN information. The MME then transfers the Diameter response message to a Packet Data Network Gateway (P-GW) through a Serving Gateway (S-GW).
Networking protocol elements, such as Diameter Routing Agents can be used to implement real-time credit-control for a variety of end users. Diameter Routing Agents designate software policy servers, such as Policy Charging and Rules Function (PCRF), to determine policy rules in a multimedia network. These software policy servers operate as a network core to query and subscribe charging databases, such as an Online Charging System (OCS) or an HSS to collect charging information and make policy decisions for a network and end users. Credit control messages are used by the Diameter Routing Agent to communicate with servers for a user's account, such as a Credit Control Request (CCR) and a Credit Control Answer (CCA).
When a software policy server is overloaded from other sources or loses connection with a Diameter Routing Agent, the Diameter Routing Agent in no longer able to determine policy and charging rules for an active data session for an end user. While communication policies from an initial policy server may contain enough data to allow an end user to continue using network services for a period of time, this can result in incorrect policies being applied or a loss of service completely during an active data session.